I have a vague memory of this sort of thing being tried before, but not enough to give out names or authors, so sorry for that. (Perhaps someone can help.) My brain storm was this: what if you could put two favourite characters from some of the great crime fiction series.
So let’s have some fun. Here’s my choice for a mash-up.
How about Michael Connelly’s Harry Bosch with Peter Robinson’s DCI Banks? Both detectives are exceptionally experienced and good at what they do, both have a tendency to do their own thing, but more importantly, both are quintessential products of their respective cultures. Bosch just breaks rules, damn the torpedoes, while Banks operates more discretely while being equally subversive in his own way. Bosch and Banks also are not afraid to rely on hunches.
I also think this combination would work best if the characters were operating in a “neutral” third country where they’re both out of their element — although I have to admit it would be interesting to see Bosch navigate the British policing system. Since Peter and Michael are good friends, it might even happen some day (are you two listening?).
So that’s my choice. How about you? And don’t forget the why part because that’s what makes this idea interesting!